When accelerating from a stop abrupt violent stops

Is it normal for this car's transmission to go at 92,000 miles? When driving from a red light it feels like the engine loses power when I hit the gas. Then boom, it stops like someone pulled the parking brake. No check engine light or anything. It kept happening until the car was too dangerous to drive. Literally abrupt violent stops. Got it towed and the machine said there was nothing wrong. It happened when the mechanic drove it though and he automatically said transmission. It never really slipped before and drove fine until it did that.