diff --git a/libs/input/VelocityTracker.cpp b/libs/input/VelocityTracker.cpp
index 7f427f2..76aaf61 100644
--- a/libs/input/VelocityTracker.cpp
+++ b/libs/input/VelocityTracker.cpp
@@ -27,6 +27,8 @@
 #include <utils/BitSet.h>
 #include <utils/Timers.h>
 
+using std::literals::chrono_literals::operator""ms;
+
 namespace android {
 
 /**
@@ -57,8 +59,14 @@
 // Some input devices do not send ACTION_MOVE events in the case where a pointer has
 // stopped.  We need to detect this case so that we can accurately predict the
 // velocity after the pointer starts moving again.
-static const nsecs_t ASSUME_POINTER_STOPPED_TIME = 40 * NANOS_PER_MS;
+static const std::chrono::duration ASSUME_POINTER_STOPPED_TIME = 40ms;
 
+static std::string toString(std::chrono::nanoseconds t) {
+    std::stringstream stream;
+    stream.precision(1);
+    stream << std::fixed << std::chrono::duration<float, std::milli>(t).count() << " ms";
+    return stream.str();
+}
 
 static float vectorDot(const float* a, const float* b, uint32_t m) {
     float r = 0;
@@ -146,18 +154,14 @@
         VelocityTracker::Strategy strategy) {
     switch (strategy) {
         case VelocityTracker::Strategy::IMPULSE:
-            if (DEBUG_STRATEGY) {
-                ALOGI("Initializing impulse strategy");
-            }
+            ALOGI_IF(DEBUG_STRATEGY, "Initializing impulse strategy");
             return std::make_unique<ImpulseVelocityTrackerStrategy>();
 
         case VelocityTracker::Strategy::LSQ1:
             return std::make_unique<LeastSquaresVelocityTrackerStrategy>(1);
 
         case VelocityTracker::Strategy::LSQ2:
-            if (DEBUG_STRATEGY && !DEBUG_IMPULSE) {
-                ALOGI("Initializing lsq2 strategy");
-            }
+            ALOGI_IF(DEBUG_STRATEGY && !DEBUG_IMPULSE, "Initializing lsq2 strategy");
             return std::make_unique<LeastSquaresVelocityTrackerStrategy>(2);
 
         case VelocityTracker::Strategy::LSQ3:
@@ -221,12 +225,11 @@
         idBits.clearLastMarkedBit();
     }
 
-    if ((mCurrentPointerIdBits.value & idBits.value)
-            && eventTime >= mLastEventTime + ASSUME_POINTER_STOPPED_TIME) {
-        if (DEBUG_VELOCITY) {
-            ALOGD("VelocityTracker: stopped for %0.3f ms, clearing state.",
-                  (eventTime - mLastEventTime) * 0.000001f);
-        }
+    if ((mCurrentPointerIdBits.value & idBits.value) &&
+        std::chrono::nanoseconds(eventTime - mLastEventTime) > ASSUME_POINTER_STOPPED_TIME) {
+        ALOGD_IF(DEBUG_VELOCITY, "VelocityTracker: stopped for %s, clearing state.",
+                 toString(std::chrono::nanoseconds(eventTime - mLastEventTime)).c_str());
+
         // We have not received any movements for too long.  Assume that all pointers
         // have stopped.
         mStrategy->clear();
@@ -281,8 +284,18 @@
     case AMOTION_EVENT_ACTION_MOVE:
     case AMOTION_EVENT_ACTION_HOVER_MOVE:
         break;
-    default:
-        // Ignore all other actions because they do not convey any new information about
+    case AMOTION_EVENT_ACTION_POINTER_UP:
+    case AMOTION_EVENT_ACTION_UP: {
+        std::chrono::nanoseconds delaySinceLastEvent(event->getEventTime() - mLastEventTime);
+        if (delaySinceLastEvent > ASSUME_POINTER_STOPPED_TIME) {
+            ALOGD_IF(DEBUG_VELOCITY,
+                     "VelocityTracker: stopped for %s, clearing state upon pointer liftoff.",
+                     toString(delaySinceLastEvent).c_str());
+            // We have not received any movements for too long.  Assume that all pointers
+            // have stopped.
+            mStrategy->clear();
+        }
+        // These actions because they do not convey any new information about
         // pointer movement.  We also want to preserve the last known velocity of the pointers.
         // Note that ACTION_UP and ACTION_POINTER_UP always report the last known position
         // of the pointers that went up.  ACTION_POINTER_UP does include the new position of
@@ -292,6 +305,10 @@
         // before adding the movement.
         return;
     }
+    default:
+        // Ignore all other actions.
+        return;
+    }
 
     size_t pointerCount = event->getPointerCount();
     if (pointerCount > MAX_POINTERS) {
@@ -438,10 +455,10 @@
 static bool solveLeastSquares(const std::vector<float>& x, const std::vector<float>& y,
                               const std::vector<float>& w, uint32_t n, float* outB, float* outDet) {
     const size_t m = x.size();
-    if (DEBUG_STRATEGY) {
-        ALOGD("solveLeastSquares: m=%d, n=%d, x=%s, y=%s, w=%s", int(m), int(n),
-              vectorToString(x).c_str(), vectorToString(y).c_str(), vectorToString(w).c_str());
-    }
+
+    ALOGD_IF(DEBUG_STRATEGY, "solveLeastSquares: m=%d, n=%d, x=%s, y=%s, w=%s", int(m), int(n),
+             vectorToString(x).c_str(), vectorToString(y).c_str(), vectorToString(w).c_str());
+
     LOG_ALWAYS_FATAL_IF(m != y.size() || m != w.size(), "Mismatched vector sizes");
 
     // Expand the X vector to a matrix A, pre-multiplied by the weights.
@@ -452,9 +469,9 @@
             a[i][h] = a[i - 1][h] * x[h];
         }
     }
-    if (DEBUG_STRATEGY) {
-        ALOGD("  - a=%s", matrixToString(&a[0][0], m, n, false /*rowMajor*/).c_str());
-    }
+
+    ALOGD_IF(DEBUG_STRATEGY, "  - a=%s",
+             matrixToString(&a[0][0], m, n, false /*rowMajor*/).c_str());
 
     // Apply the Gram-Schmidt process to A to obtain its QR decomposition.
     float q[n][m]; // orthonormal basis, column-major order
@@ -473,9 +490,7 @@
         float norm = vectorNorm(&q[j][0], m);
         if (norm < 0.000001f) {
             // vectors are linearly dependent or zero so no solution
-            if (DEBUG_STRATEGY) {
-                ALOGD("  - no solution, norm=%f", norm);
-            }
+            ALOGD_IF(DEBUG_STRATEGY, "  - no solution, norm=%f", norm);
             return false;
         }
 
@@ -518,9 +533,8 @@
         }
         outB[i] /= r[i][i];
     }
-    if (DEBUG_STRATEGY) {
-        ALOGD("  - b=%s", vectorToString(outB, n).c_str());
-    }
+
+    ALOGD_IF(DEBUG_STRATEGY, "  - b=%s", vectorToString(outB, n).c_str());
 
     // Calculate the coefficient of determination as 1 - (SSerr / SStot) where
     // SSerr is the residual sum of squares (variance of the error),
@@ -546,11 +560,11 @@
         sstot += w[h] * w[h] * var * var;
     }
     *outDet = sstot > 0.000001f ? 1.0f - (sserr / sstot) : 1;
-    if (DEBUG_STRATEGY) {
-        ALOGD("  - sserr=%f", sserr);
-        ALOGD("  - sstot=%f", sstot);
-        ALOGD("  - det=%f", *outDet);
-    }
+
+    ALOGD_IF(DEBUG_STRATEGY, "  - sserr=%f", sserr);
+    ALOGD_IF(DEBUG_STRATEGY, "  - sstot=%f", sstot);
+    ALOGD_IF(DEBUG_STRATEGY, "  - det=%f", *outDet);
+
     return true;
 }
 
@@ -673,11 +687,11 @@
             outEstimator->time = newestMovement.eventTime;
             outEstimator->degree = degree;
             outEstimator->confidence = xdet * ydet;
-            if (DEBUG_STRATEGY) {
-                ALOGD("estimate: degree=%d, xCoeff=%s, yCoeff=%s, confidence=%f",
-                      int(outEstimator->degree), vectorToString(outEstimator->xCoeff, n).c_str(),
-                      vectorToString(outEstimator->yCoeff, n).c_str(), outEstimator->confidence);
-            }
+
+            ALOGD_IF(DEBUG_STRATEGY, "estimate: degree=%d, xCoeff=%s, yCoeff=%s, confidence=%f",
+                     int(outEstimator->degree), vectorToString(outEstimator->xCoeff, n).c_str(),
+                     vectorToString(outEstimator->yCoeff, n).c_str(), outEstimator->confidence);
+
             return true;
         }
     }
@@ -1185,9 +1199,10 @@
     outEstimator->time = newestMovement.eventTime;
     outEstimator->degree = 2; // similar results to 2nd degree fit
     outEstimator->confidence = 1;
-    if (DEBUG_STRATEGY) {
-        ALOGD("velocity: (%.1f, %.1f)", outEstimator->xCoeff[1], outEstimator->yCoeff[1]);
-    }
+
+    ALOGD_IF(DEBUG_STRATEGY, "velocity: (%.1f, %.1f)", outEstimator->xCoeff[1],
+             outEstimator->yCoeff[1]);
+
     if (DEBUG_IMPULSE) {
         // TODO(b/134179997): delete this block once the switch to 'impulse' is complete.
         // Calculate the lsq2 velocity for the same inputs to allow runtime comparisons
diff --git a/libs/input/tests/VelocityTracker_test.cpp b/libs/input/tests/VelocityTracker_test.cpp
index a87b187..4a445de 100644
--- a/libs/input/tests/VelocityTracker_test.cpp
+++ b/libs/input/tests/VelocityTracker_test.cpp
@@ -26,7 +26,9 @@
 #include <gui/constants.h>
 #include <input/VelocityTracker.h>
 
-using namespace std::chrono_literals;
+using std::literals::chrono_literals::operator""ms;
+using std::literals::chrono_literals::operator""ns;
+using std::literals::chrono_literals::operator""us;
 using android::base::StringPrintf;
 
 namespace android {
@@ -149,8 +151,7 @@
         if (i == 0) {
             action = AMOTION_EVENT_ACTION_DOWN;
             EXPECT_EQ(1U, pointerCount) << "First event should only have 1 pointer";
-        } else if (i == motions.size() - 1) {
-            EXPECT_EQ(1U, pointerCount) << "Last event should only have 1 pointer";
+        } else if ((i == motions.size() - 1) && pointerCount == 1) {
             action = AMOTION_EVENT_ACTION_UP;
         } else {
             const MotionEventEntry& previousEntry = motions[i-1];
@@ -195,7 +196,7 @@
 
 static void computeAndCheckVelocity(const VelocityTracker::Strategy strategy,
                                     const std::vector<MotionEventEntry>& motions, int32_t axis,
-                                    float targetVelocity) {
+                                    float targetVelocity, uint32_t pointerId = DEFAULT_POINTER_ID) {
     VelocityTracker vt(strategy);
     float Vx, Vy;
 
@@ -204,7 +205,7 @@
         vt.addMovement(&event);
     }
 
-    vt.getVelocity(DEFAULT_POINTER_ID, &Vx, &Vy);
+    vt.getVelocity(pointerId, &Vx, &Vy);
 
     switch (axis) {
     case AMOTION_EVENT_AXIS_X:
@@ -846,13 +847,71 @@
 
     // Velocity should actually be zero, but we expect 0.016 here instead.
     // This is close enough to zero, and is likely caused by division by a very small number.
-    computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, -0.016);
-    computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y, -0.016);
+    computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, 0);
+    computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_Y, 0);
     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X, 0);
     computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_Y, 0);
 }
 
 /**
+ * ================= Pointer liftoff ===============================================================
+ */
+
+/**
+ * The last movement of a pointer is always ACTION_POINTER_UP or ACTION_UP. If there's a short delay
+ * between the last ACTION_MOVE and the next ACTION_POINTER_UP or ACTION_UP, velocity should not be
+ * affected by the liftoff.
+ */
+TEST_F(VelocityTrackerTest, ShortDelayBeforeActionUp) {
+    std::vector<MotionEventEntry> motions = {
+            {0ms, {{10, 0}}}, {10ms, {{20, 0}}}, {20ms, {{30, 0}}}, {30ms, {{30, 0}}}, // ACTION_UP
+    };
+    computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X,
+                            1000);
+    computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, 1000);
+}
+
+/**
+ * The last movement of a single pointer is ACTION_UP. If there's a long delay between the last
+ * ACTION_MOVE and the final ACTION_UP, velocity should be reported as zero because the pointer
+ * should be assumed to have stopped.
+ */
+TEST_F(VelocityTrackerTest, LongDelayBeforeActionUp) {
+    std::vector<MotionEventEntry> motions = {
+            {0ms, {{10, 0}}},
+            {10ms, {{20, 0}}},
+            {20ms, {{30, 0}}},
+            {3000ms, {{30, 0}}}, // ACTION_UP
+    };
+    computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X, 0);
+    computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, 0);
+}
+
+/**
+ * The last movement of a pointer is always ACTION_POINTER_UP or ACTION_UP. If there's a long delay
+ * before ACTION_POINTER_UP event, the movement should be assumed to have stopped.
+ * The final velocity should be reported as zero for all pointers.
+ */
+TEST_F(VelocityTrackerTest, LongDelayBeforeActionPointerUp) {
+    std::vector<MotionEventEntry> motions = {
+            {0ms, {{10, 0}}},
+            {10ms, {{20, 0}, {100, 0}}},
+            {20ms, {{30, 0}, {200, 0}}},
+            {30ms, {{30, 0}, {300, 0}}},
+            {40ms, {{30, 0}, {400, 0}}},
+            {3000ms, {{30, 0}}}, // ACTION_POINTER_UP
+    };
+    computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X, 0,
+                            /*pointerId*/ 0);
+    computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, 0,
+                            /*pointerId*/ 0);
+    computeAndCheckVelocity(VelocityTracker::Strategy::IMPULSE, motions, AMOTION_EVENT_AXIS_X, 0,
+                            /*pointerId*/ 1);
+    computeAndCheckVelocity(VelocityTracker::Strategy::LSQ2, motions, AMOTION_EVENT_AXIS_X, 0,
+                            /*pointerId*/ 1);
+}
+
+/**
  * ================== Tests for least squares fitting ==============================================
  *
  * Special care must be taken when constructing tests for LeastSquaresVelocityTrackerStrategy