1991 trooper starting problem

An emergency visit to take the dog to the vet required the use of the Trooper that had not been driven long distances in months. Drove 20 miles to the vet fine. On the way back, the battey light came on and the car started to die so pulled over. The car would not start again only going click when the key was turned on. A nice man stopped and tried to help compression start (toed it pretty fast) it but would not start at all - he said bad gas. My thought is that the problem is still in the starter since it won't turn over. The battery is good, connections are cleaned. Any ideas what the problem is (or do I have several?). Thanks greatly!